Decode display/screen of current patch

Author: mungewell

decode_screens.py

@@ -0,0 +1,99 @@
+#!/usr/bin/python
+#
+# Script decode 'screen data' from Zoom G1Four
+# (c) Simon Wood, 10 Dec 2020
+#
+# read with:
+# $ amidi -p hw:1,0,0 -S 'F0 52 00 6e 64 02 00 09 00 F7' -r temp.bin -t 2
+#
+
+from construct import *
+
+#--------------------------------------------------
+# Define ZPTC file format using Construct (v2.9)
+# requires:
+# https://github.com/construct/construct
+
+Type = Struct(
+    Enum(Byte,
+        VALUE  = 0x00,
+        NAME   = 0x01,
+        INVERT = 0x07,
+    ),
+)
+
+Info = Struct(
+    "screen1" / Byte,
+    "param1" / Byte,
+    "type1" / Embedded(Type),
+    "invert1" / Byte,
+    "value" / PaddedString(10, "ascii"),
+
+    "screen2" / Byte,
+    "param2" / Byte,
+    "type2" / Embedded(Type),
+    "invert2" / Byte,
+    "name" / PaddedString(10, "ascii"),
+)
+
+Screen = Struct(
+    "info" / Array(6, Info),
+)
+
+Display = Struct(
+    GreedyRange(Const(b"\x00")),        # get rid of leading zeros
+    Const(b"\xf0\x52\x00\x6e\x64\x01"), 
+    "screens" / GreedyRange(Screen),
+    #Const(b"\xf7"),                    # not seen if we ask for too
+                                        # many screens worth of data
+)
+
+#--------------------------------------------------
+def main():
+    from optparse import OptionParser
+
+    usage = "usage: %prog [options] FILENAME"
+    parser = OptionParser(usage)
+    parser.add_option("-d", "--dump",
+        help="dump configuration to text",
+        action="store_true", dest="dump")
+
+    (options, args) = parser.parse_args()
+    
+    if len(args) != 1:
+        parser.error("FILE not specified")
+
+    infile = open(args[0], "rb")
+    if not infile:
+        sys.exit("Unable to open FILE for reading")
+    else:
+        data = infile.read()
+    infile.close()
+
+    if data:
+        config = Display.parse(data)
+        if options.dump:
+            print(config)
+
+        for screen in config['screens']:
+            for info in screen['info']:
+                if info['param1'] == 0:
+                    if info['name'] == "Dummy":
+                        on_off = None
+                    else:
+                        if info['value'] == "1":
+                            on_off = "On"
+                        else:
+                            on_off = "Off"
+                        print("---")
+                elif info['param1'] == 1:
+                    if on_off:
+                        print("Effect: %s (%s)" % (info['name'], on_off))
+                else:
+                    if info['name'] != "Dummy":
+                        print("%s : %s" % (info['name'], info['value']))
+
+
+if __name__ == "__main__":
+    main()
+

readme.md

@@ -194,7 +194,16 @@ $ amidi -p hw:1,0,0 -S 'f0 52 00 6e 29 f7'
 Request Specific Patch Info (note: slightly longer reply).
 ```
 $ amidi -p hw:1,0,0 -S 'F0 52 00 6e 09 00 04 09 F7'
-                                           ^ ^^
-                                           | ++-- Program (0..9)
+                                           ^  ^
+                                           |  +-- Program (0..9)
                                            +----- Bank (0..4)
 ```
+
+Read display information of current patch, which is mostly text based.
+(can be saved to a file and processed with 'decode_screens.py')
+```
+$ amidi -p hw:2,0,0 -S 'F0 52 00 6e 64 02 00 00 00 F7'
+                                           ^  ^
+                                           |  +-- End Screen
+                                           +----- Start Screen
+```